Hippocampal neurons with stable excitatory connectivity become part of neuronal representations

Experiences are represented in the brain by patterns of neuronal activity. Ensembles of neurons representing experience undergo activity-dependent plasticity and are important for learning and recall. They are thus considered cellular engrams of memory. Yet, the cellular events that bias neurons to become part of a neuronal representation are largely unknown. In rodents, turnover of structural connectivity has been proposed to underlie the turnover of neuronal representations and also to be a cellular mechanism defining the time duration for which memories are stored in the hippocampus. If these hypotheses are true, structural dynamics of connectivity should be involved in the formation of neuronal representations and concurrently important for learning and recall. To tackle these questions, we used deep-brain 2-photon (2P) time-lapse imaging in transgenic mice in which neurons expressing the Immediate Early Gene (IEG) Arc (activity-regulated cytoskeleton-associated protein) could be permanently labeled during a specific time window. This enabled us to investigate the dynamics of excitatory synaptic connectivity-using dendritic spines as proxies-of hippocampal CA1 (cornu ammonis 1) pyramidal neurons (PNs) becoming part of neuronal representations exploiting Arc as an indicator of being part of neuronal representations. We discovered that neurons that will prospectively express Arc have slower turnover of synaptic connectivity, thus suggesting that synaptic stability prior to experience can bias neurons to become part of representations or possibly engrams. We also found a negative correlation between stability of structural synaptic connectivity and the ability to recall features of a hippocampal-dependent memory, which suggests that faster structural turnover in hippocampal CA1 might be functional for memory

The use of skin traction in the adult patients with proximal femur fracture. What are the effects, advantages and disadvantages? A scoping review

Background: Hip surgery is normally the chosen therapy for proximal femur fractures. Surgery within 24–48 h after hip fracture is recommended, but surgery may not always be performed promptly. Consequently, skin-traction is applied to reduce complications. The purpose of this review is to assess both advantages and disadvantages of skin traction. Methods: A scoping review was conducted. The research question was: which are the effects of skin traction, its advantages and disadvantages in adult patients with proximal femur fractures hospitalised in orthopaedic wards? The search was done in the databases PubMed, CINAHL, Cochrane, Embase, DOAJ, ClinicalTrials.gov and OpenDissertation. Results: 9 records were included, skin traction effects were summarised in 7 categories: pain, pressure sores, comfort and relaxation, thromboembolism, damage from adhesive, complications and quality of care. The possible advantage is pain reduction between 24 and 60 h, the possible disadvantage is skin damage. Discussion and conclusion: The routine use of skin traction does not appear recommended, but more consistent evidence is necessary to make clinic decisions. Future RCTs could focus on the effects of skin traction 24–60 h after hospitalisation and before surgery

Live Imaging at the Onset of Cortical Neurogenesis Reveals Differential Appearance of the Neuronal Phenotype in Apical versus Basal Progenitor Progeny

The neurons of the mammalian brain are generated by progenitors dividing either at the apical surface of the ventricular zone (neuroepithelial and radial glial cells, collectively referred to as apical progenitors) or at its basal side (basal progenitors, also called intermediate progenitors). For apical progenitors, the orientation of the cleavage plane relative to their apical-basal axis is thought to be of critical importance for the fate of the daughter cells. For basal progenitors, the relationship between cell polarity, cleavage plane orientation and the fate of daughter cells is unknown. Here, we have investigated these issues at the very onset of cortical neurogenesis. To directly observe the generation of neurons from apical and basal progenitors, we established a novel transgenic mouse line in which membrane GFP is expressed from the beta-III-tubulin promoter, an early pan-neuronal marker, and crossed this line with a previously described knock-in line in which nuclear GFP is expressed from the Tis21 promoter, a pan-neurogenic progenitor marker. Mitotic Tis21-positive basal progenitors nearly always divided symmetrically, generating two neurons, but, in contrast to symmetrically dividing apical progenitors, lacked apical-basal polarity and showed a nearly randomized cleavage plane orientation. Moreover, the appearance of beta-III-tubulin–driven GFP fluorescence in basal progenitor-derived neurons, in contrast to that in apical progenitor-derived neurons, was so rapid that it suggested the initiation of the neuronal phenotype already in the progenitor. Our observations imply that (i) the loss of apical-basal polarity restricts neuronal progenitors to the symmetric mode of cell division, and that (ii) basal progenitors initiate the expression of neuronal phenotype already before mitosis, in contrast to apical progenitors

The interaction between a sexually transferred steroid hormone and a female protein regulates oogenesis in the malaria mosquito anopheles gambiae

Molecular interactions between male and female factors during mating profoundly affect the reproductive behavior and physiology of female insects. In natural populations of the malaria mosquito Anopheles gambiae, blood-fed females direct nutritional resources towards oogenesis only when inseminated. Here we show that the mating-dependent pathway of egg development in these mosquitoes is regulated by the interaction between the steroid hormone 20-hydroxy-ecdysone (20E) transferred by males during copulation and a female Mating-Induced Stimulator of Oogenesis (MISO) protein. RNAi silencing of MISO abolishes the increase in oogenesis caused by mating in blood-fed females, causes a delay in oocyte development, and impairs the function of male-transferred 20E. Co-immunoprecipitation experiments show that MISO and 20E interact in the female reproductive tract. Moreover MISO expression after mating is induced by 20E via the Ecdysone Receptor, demonstrating a close cooperation between the two factors. Male-transferred 20E therefore acts as a mating signal that females translate into an increased investment in egg development via a MISO-dependent pathway. The identification of this male–female reproductive interaction offers novel opportunities for the control of mosquito populations that transmit malaria

Metabolic disorders across hepatocellular carcinoma in Italy

BACKGROUND: Metabolic disorders are well-known risk factors for HCC. Conversely, their impact on the natural history of HCC is not established. This study aimed at evaluating the impact of metabolic disorders on clinical features, treatment and survival of HCC patients regardless of its aetiology. METHODS: We analysed the ITA.LI.CA database regarding 839 HCC patients prospectively collected. The following metabolic features were analysed: BMI, diabetes, arterial hypertension, hypercholesterolaemia and hypertriglyceridaemia. According to these features, patients were divided into 3 groups: 0-1, 2 and 3-5 metabolic features. RESULTS: As compared with patients with 0-1 metabolic features, patients with 3-5 features showed lower percentage of HCC diagnosis on surveillance (P = .021), larger tumours (P = .038), better liver function (higher percentage of Child-Pugh class A [P = .007] and MELD < 10 [P = .003]), higher percentage of metastasis (P = .024) and lower percentage of portal vein thrombosis (P = .010). The BCLC stage and treatment options were similar among the 3 groups, with the exception of a less frequent access to loco-regional therapies for BCLC stage B patients with 3-5 features (P = .012). Overall survival and survival according to BCLC stage and/or treatment did not significantly differ among the 3 groups. Only using a probabilistic sensitivity analysis, diabetic patients showed a lower survival (P = .046). MELD score, HCC morphology, nodule size, BCLC stage, portal vein thrombosis and metastasis were independent predictors of lead-time adjusted survival. CONCLUSIONS: Our "real world" study suggests that metabolic disorders shape the clinical presentation of HCC but do not seem to play a major role in setting patient survival.Background: Metabolic disorders are well-known risk factors for HCC. Conversely, their impact on the natural history of HCC is not established. This study aimed at evaluating the impact of metabolic disorders on clinical features, treatment and survival of HCC patients regardless of its aetiology. Methods: We analysed the ITA.LI.CA database regarding 839 HCC patients prospectively collected. The following metabolic features were analysed: BMI, diabetes, arterial hypertension, hypercholesterolaemia and hypertriglyceridaemia. According to these features, patients were divided into 3 groups: 0-1, 2 and 3-5 metabolic features. Results: As compared with patients with 0-1 metabolic features, patients with 3-5 features showed lower percentage of HCC diagnosis on surveillance (P =.021), larger tumours (P =.038), better liver function (higher percentage of Child-Pugh class A [P =.007] and MELD < 10 [P =.003]), higher percentage of metastasis (P =.024) and lower percentage of portal vein thrombosis (P =.010). The BCLC stage and treatment options were similar among the 3 groups, with the exception of a less frequent access to loco-regional therapies for BCLC stage B patients with 3-5 features (P =.012). Overall survival and survival according to BCLC stage and/or treatment did not significantly differ among the 3 groups. Only using a probabilistic sensitivity analysis, diabetic patients showed a lower survival (P =.046). MELD score, HCC morphology, nodule size, BCLC stage, portal vein thrombosis and metastasis were independent predictors of lead-time adjusted survival. Conclusions: Our \u201creal world\u201d study suggests that metabolic disorders shape the clinical presentation of HCC but do not seem to play a major role in setting patient survival

Fresh-blood-free diet for rearing malaria mosquito vectors

Mosquito breeding depends on the supply of fresh vertebrate blood, a major bottleneck for large-scale production of Anopheles spp. Feeding alternatives to fresh blood are thus a priority for research, outdoor large-cage trials and control interventions. Several artificial meal compositions were tested and Anopheles oogenesis, egg laying and development into the next generation of adult mosquitoes were followed. We identified blood-substitute-diets that supported ovarian development, egg maturation and fertility as well as, low progeny larval mortality, and normal development of offspring into adult mosquitoes. The formulated diet is an effective artificial meal, free of fresh blood that mimics a vertebrate blood meal and represents an important advance for the sustainability of Anopheles mosquito rearing in captivity.Agência financiadora / Número do subsídio Bill and Melinda Gates Foundation OPP1138841 Fundacao para a Ciencia e Tecnologia GHTM - UID/Multi/04413/201 CCMAR - UID/Multi/04326/2013 UID/Multi/04326/2013 RF SFRH/BPD/89811/2012 FAPEAM, Brazil 19716.UNI472.2459.20022014info:eu-repo/semantics/publishedVersio

Infections with Immunogenic Trypanosomes Reduce Tsetse Reproductive Fitness: Potential Impact of Different Parasite Strains on Vector Population Structure

The parasite Trypanosoma brucei rhodesiense and its insect vector Glossina morsitans morsitans were used to evaluate the effect of parasite clearance (resistance) as well as the cost of midgut infections on tsetse host fitness. Tsetse flies are viviparous and have a low reproductive capacity, giving birth to only 6–8 progeny during their lifetime. Thus, small perturbations to their reproductive fitness can have a major impact on population densities. We measured the fecundity (number of larval progeny deposited) and mortality in parasite-resistant tsetse females and untreated controls and found no differences. There was, however, a typanosome-specific impact on midgut infections. Infections with an immunogenic parasite line that resulted in prolonged activation of the tsetse immune system delayed intrauterine larval development resulting in the production of fewer progeny over the fly's lifetime. In contrast, parasitism with a second line that failed to activate the immune system did not impose a fecundity cost. Coinfections favored the establishment of the immunogenic parasites in the midgut. We show that a decrease in the synthesis of Glossina Milk gland protein (GmmMgp), a major female accessory gland protein associated with larvagenesis, likely contributed to the reproductive lag observed in infected flies. Mathematical analysis of our empirical results indicated that infection with the immunogenic trypanosomes reduced tsetse fecundity by 30% relative to infections with the non-immunogenic strain. We estimate that a moderate infection prevalence of about 26% with immunogenic parasites has the potential to reduce tsetse populations. Potential repercussions for vector population growth, parasite–host coevolution, and disease prevalence are discussed

Laser ablation is superior to TACE in large-sized hepatocellular carcinoma: A pilot case-control study

Background:Limited therapies are available for large ( 6540 mm) unresectable hepatocellular carcinoma (HCC). Currently, the standard treatment with transarterial chemoembolisation (TACE) is unsatisfactory with high recurrence rate and limited effect on survival. Laser Ablation (LA) has emerged as a relatively new technique characterized by high efficacy and good safety. This study is aimed to evaluate the efficacy of LA in comparison to TACE in patients with large HCC. Methods: Eighty-two patients with a single HCC nodule 6540 mm (BCLC stage A or B) were enrolled in this case-control study. Forty-one patients were treated with LA and 41 patients were treated with TACE. Response to therapy was evaluated according to the mRECIST criteria. Survival was calculated with Kaplan-Meier from the time of cancer diagnosis to death with values censored at the date of the last follow-up. Results: Twenty-six (63.4%) and 8 (19.5%) patients had a complete response after LA and TACE, respectively (p < 0.001). Subsequently we stratified the HCCs in 3 categories according to the nodule size: 40-50 mm, 51-60 mm, and > 60 mm. LA resulted superior to TACE especially in nodules ranging between 51 and 60 mm in diameter, with a complete response rate post-LA and post-TACE of 75% and 14.3%, respectively (p = 0.0133). The 36 months cumulative survival rate in patients treated with LA and TACE was 55.4% and 48.8%, respectively. The disease recurrence rates after LA and TACE were 19.5% and 75.0%, respectively. Conclusions: LA is a more effective therapeutic option than TACE in patients with solitary large HCC

Polyandry Is a Common Event in Wild Populations of the Tsetse Fly Glossina fuscipes fuscipes and May Impact Population Reduction Measures

Glossina fuscipes fuscipes is the most common tsetse species in Uganda where it is responsible for transmitting Trypanosoma brucei rhodensiense and Trypanosoma brucei gambiense parasites causing sleeping sickness in humans in addition to related trypanosomes that cause Nagana in cattle. An understanding of the reproductive biology of this vector is essential for the application of sustainable control/eradication methods such as Sterile Insect Technique (SIT). We have analysed the number of times a female mates in the wild as this aspect of the reproductive behaviour may affect the stability and size of populations. We provide evidence that remating is a common event in the wild and females store sperm from multiple males, which may potentially be used for insemination. In vector eradication programmes, re-infestation of cleared areas and/or in cases of residual populations, the occurrence of remating may unfortunately enhance the reproductive potential of the re-invading propagules. We suggest that population age structure may influence remating frequency. Considering the seasonal demographic changes that this fly undergoes during the dry and wet seasons, control programmes based on SIT should release large numbers of sterile males, even in residual surviving target populations, in the dry season

Transcriptome Analysis of the Oriental Fruit Fly (Bactrocera dorsalis)

The oriental fruit fly, Bactrocera dorsalis (Hendel), is one of the most economically important pests in the world, causing serious damage to fruit production. However, lack of genetic information on this organism is an obstacle to understanding the mechanisms behind its development and its ability to resist insecticides. Analysis of the B. dorsalis transcriptome and its expression profile data is essential to extending the genetic information resources on this species, providing a shortcut that will support studies on B. dorsalis.We performed de novo assembly of a transcriptome using short read sequencing technology (Illumina). The results generated 484,628 contigs, 70,640 scaffolds, and 49,804 unigenes. Of those unigenes, 27,455 (55.13%) matched known proteins in the NCBI database, as determined by BLAST search. Clusters of orthologous groups (COG), gene orthology (GO), and the Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations were performed to better understand the functions of these unigenes. Genes related to insecticide resistance were analyzed in additional detail. Digital gene expression (DGE) libraries showed differences in gene expression profiles at different developmental stages (eggs, third-instar larvae, pupae, and adults). To confirm the DGE results, the expression profiles of six randomly selected genes were analyzed.This transcriptome greatly improves our genetic understanding of B. dorsalis and makes a huge number of gene sequences available for further study, including both genes of known importance and genes of unknown function. The DGE data provide comprehensive insight into gene expression profiles at different developmental stages. This facilitates the study of the role of each gene in the developmental process and in insecticide resistance